Docker and Portainer

Posted under » Ubuntu » Linux on 27 Apr 2024

Right now I don't have time to explain why we should be using docker but it is hard to ignore it. Install according to your specs. Maybe next time I explain in detail.

$ apt install apt-transport-https ca-certificates curl software-properties-common
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
$ add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu jammy stable"
$ apt-cache policy docker-ce
$ apt install docker-ce
$ systemctl status docker
$ docker info

Docker containers are built from Docker images. By default, Docker pulls these images from Docker Hub. Let's test if we can pull an image.

$ docker run hello-world

To look at your local images

$ docker images

To see running dockers

$ docker ps
$ docker ps -a

To start a stopped container, use docker start, followed by the container ID. To stop a running container, use docker stop, followed by the container ID or namei. Once you’ve decided you no longer need a container anymore, remove it with the docker rm.

$ docker start 1c08a7a0d0e4
$ docker stop ubuntu
$ docker rm ubuntu

Maybe this is all too hard to remember so I recommend that you docker this app called Portainer

Portainer needs persisting data (for storing user password for example). Let's create a docker volume to store this data.

$ docker volume create portainer_data
$ docker volume inspect portainer_data 

Now run it on port 9000

$ docker run -d -p 9000:9000 --name=portainer --restart=always 
  -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce

Here is the detail of each option:

• docker run is the base command to start a container
• -d means detach. It runs the container in background.
• -p expose UI over the port 9000, portainer GUI will be at URL hostname:9000
• --name=portainer names the container portainer
• --restart=always always restart Portainer (after a crash or at machine or deamon restart)
• -v /var/run/docker.sock:/var/run/docker.sock mounts the volume /var/run/docker.sock from the host machine to the Portainer container.
  /var/run/docker.sock is actually the Docker daemon socket. Portainer needs this socket to get Docker status.
• -v portainer_data:/data mounts the volume created previously portainer/portainer-ce is the name of the Portainer Community Edition image.

The first time Portainer starts, it asks you to set a password. The password must be at least 12 characters. Once the password is entered, you are in business.